Thin airfoil ceiling fan blade

ABSTRACT

A fan blade comprising a root end, a blade region, and a transition region. Wherein each of the root end and blade region comprise a unique profile, and wherein the transition region comprises a profile which transitions the root end profile to the blade region profile. The root end profile comprises a substantially convex top surface, a substantially concave domed sector, and reliefs to allow for the root end to be coupled with a similarly shaped fan hub extrusion. The blade region profile comprises a substantially convex top surface and bottom surface which terminate at a leading edge and trailing edge. The blade region slopes upward along a length of the blade region and terminates at a curved tip.

PRIORITY

This application claims priority to U.S. Provisional Patent ApplicationSer. No. 61/588,932, filed Jan. 20, 2012, entitled “Thin Airfoil CeilingFan Blade,” the disclosure of which is incorporated by reference herein.

BACKGROUND

A variety of fan systems have been made and used over the years in avariety of contexts. For instance, various ceiling fans are disclosed inU.S. Pat. No. 7,284,960, entitled “Fan Blades,” issued Oct. 23, 2007;U.S. Pat. No. 6,244,821, entitled “Low Speed Cooling Fan,” issued Jun.12, 2001; U.S. Pat. No. 6,939,108, entitled “Cooling Fan with ReinforcedBlade,” issued Sep. 6, 2005; and U.S. Pat. No. D607,988, entitled“Ceiling Fan,” issued Jan. 12, 2010. The disclosures of each of thoseU.S. patents are incorporated by reference herein. Additional exemplaryfans are disclosed in U.S. Pat. No. 8,079,823, entitled “Fan Blades,”issued Dec. 20, 2011; U.S. Pat. Pub. No. 2009/0208333, entitled “CeilingFan System with Brushless Motor,” published Aug. 20, 2009; and U.S. Pat.Pub. No. 2010/0278637, entitled “Ceiling Fan with Variable Blade Pitchand Variable Speed Control,” published Nov. 4, 2010, the disclosures ofwhich are also incorporated by reference herein. It should be understoodthat teachings herein may be incorporated into any of the fans describedin any of the above-referenced patents, publications, or patentapplications

A fan blade or airfoil may include one or more upper air fences and/orone or more lower air fences at any suitable position(s) along thelength of the fan blade or airfoil. Merely exemplary air fences aredescribed in U.S. Pat. Pub. No. 2011/0081246, entitled “Air Fence forFan Blade,” published Apr. 7, 2011, the disclosure of which isincorporated by reference herein. Alternatively, any other suitable typeof component or feature may be positioned along the length of a fanblade or airfoil; or such components or features may simply be omitted.

The outer tip of a fan blade or airfoil may be finished by the additionof an aerodynamic tip or winglet. Merely exemplary winglets aredescribed in U.S. Pat. No. 7,252,478, entitled “Fan BladeModifications,” issued Aug. 7, 2007, the disclosure of which isincorporated by reference herein. Additional winglets are described inU.S. Pat. No. 7,934,907, entitled “Cuffed Fan Blade Modifications,”issued May 3, 2011, the disclosure of which is incorporated by referenceherein. Still other exemplary winglets are described in U.S. Pat. No.D587,799, entitled “Winglet for a Fan Blade,” issued Mar. 3, 2009, thedisclosure of which is incorporated by reference herein. In somesettings, such winglets may interrupt the outward flow of air at the tipof a fan blade, redirecting the flow to cause the air to pass over thefan blade in a perpendicular direction, and also ensuring that theentire air stream exits over the trailing edge of the fan blade andreducing tip vortex formation. In some settings, this may result inincreased efficiency in operation in the region of the tip of the fanblade. In other variations, an angled extension may be added to a fanblade or airfoil, such as the angled airfoil extensions described inU.S. Pat. No. 8,162,613, entitled “Angled Airfoil Extension for FanBlade,” issued Apr. 24, 2012, the disclosure of which is incorporated byreference herein. Other suitable structures that may be associated withan outer tip of an airfoil or fan blade will be apparent to those ofordinary skill in the art. Alternatively, the outer tip of an airfoil orfan blade may be simply closed (e.g., with a cap or otherwise, etc.), ormay lack any similar structure at all.

The interface of a fan blade and a fan hub may also be provided in avariety of ways. For instance, an interface component is described inU.S. Pat. No. 8,147,204, entitled “Aerodynamic Interface Component forFan Blade,” issued Apr. 3, 2012, the disclosure of which is incorporatedby reference herein. In addition, or in the alternative, the fan blademay include a retention system that couples the tip of a fan blade to anattachment point on the fan hub via a cable running through the fanblade, such as that disclosed in U.S. Pat. Pub. No. 2011/0262278,published Oct. 27, 2011. Alternatively, the interface of a fan blade anda fan hub may include any other component or components, or may lack anysimilar structure at all.

Fans may also include a variety of mounting structures. For instance, afan mounting structure is disclosed in U.S. Pat. No. 8,152,453, entitled“Ceiling Fan with Angled Mounting,” issued Apr. 10, 2012, the disclosureof which is incorporated herein. Of course, a fan need not be mounted toa ceiling or other overhead structure, and instead may be mounted to awall or to the ground. For instance, a fan may be supported on the topof a post that extends upwardly from the ground. Examples of suchmounting structures are shown in U.S. Design Pat. No. D635,237, entitled“Fan with Ground Support,” issued Mar. 29, 2011, the disclosure of whichis incorporated by reference herein; U.S. Design Pat. No. D641,075,entitled “Fan with Ground Support and Winglets,” issued Jul. 5, 2011,the disclosure of which is incorporated by reference herein; and U.S.Pat. App. No. 61/720,077, entitled “Fan Mounting System,” filed Oct. 30,2012, the disclosure of which is incorporated by reference herein.Alternatively, any other suitable mounting structures and/or mountingtechniques may be used in conjunction with embodiments described herein.

It should also be understood that a fan may include sensors or otherfeatures that are used to control, at least in part, operation of a fansystem. For instance, such fan systems are disclosed in U.S. Pat. No.8,147,182, entitled “Ceiling Fan with Concentric Stationary Tube andPower-Down Features,” issued Apr. 3, 2012, the disclosure of which isincorporated by reference herein; U.S. Pat. No. 8,123,479, entitled“Automatic Control System and Method to Minimize Oscillation in CeilingFans,” issued Feb. 28, 2012, the disclosure of which is incorporated byreference herein; U.S. Pat. Pub. No. 2010/0291858, entitled “AutomaticControl System for Ceiling Fan Based on Temperature Differentials,”published Nov. 18, 2010, the disclosure of which is incorporated byreference herein; U.S. Provisional Patent App. No. 61/165,582, entitled“Fan with Impact Avoidance System Using Infrared,” filed Apr. 1, 2009,the disclosure of which is incorporated by reference herein; and U.S.Pat. App. No. 61/720,679, entitled “Integrated Thermal Comfort ControlSystem Utilizing Circulating Fans,” filed Oct. 31, 2012, the disclosureof which is incorporated by reference herein. Alternatively, any othersuitable control systems/features may be used in conjunction withembodiments described herein.

In some settings, it may be desirable to replicate or approximate thefunction of a winglet in a component that may be located at a positionon a fan blade other than at the free end of the fan blade. Forinstance, such components are disclosed in U.S. Pat. Pub. No.2011/0081246, entitled “Air Fence For Fan Blade,” published Apr. 7,2011, the disclosure of which is incorporated by reference herein. Sucha component may provide an effect on fan efficiency similar to theeffect provide by a winglet, albeit at one or more additional regions ofthe fan blade. In particular, such a component or accessory may serve asan aerodynamic guide or air fence, interrupting slippage of air alongthe length or longitudinal axis of the fan blade; and redirecting theair flow to a direction perpendicular to the longitudinal axis of thefan blade, above and/or below the fan blade.

In some ceiling fans, flat planar blades are used by inclining theblades at an angle of approximately ten to twenty degrees from thehorizontal to displace airflow in a downward direction. These flatblades might not be aerodynamically efficient in some settings.Accordingly, to move a given volume of air, the fan must operate at ahigher speed, thereby consuming more electricity. In addition, theseflat blades might be manufactured from wood or fiberboard, harvestedfrom trees, such as Monterey Pine, which typically take 25-30 years toreach maturity. Since the regrowth time of the raw materials may exceedthe lifespan of the ceiling fan, continued production in this manner isnot an environmentally sustainable practice.

While flat planar blades have been used, attempts have been made toimprove upon ceiling fan blade designs. For example, Parker, et al, U.S.Pat. No. 6,039,541, issued Mar. 21, 2000, describes a ceiling fan bladethat includes the SD7032, GM15, MA409, and Hibbs 504 airfoils. Airfoilsof this type may operate with higher coefficients of lift versus angleof attack at Reynolds numbers greater than 100,000. In the instance of afan blade with a chord length of 10.16 centimeters (4 inches) and bladespan with the root located 22.5 centimeters (9 inches) from the centerof rotation and a tip located 76.2 centimeters (30 inches) from thecenter of rotation, operating at 50 rotations per minute may experienceReynolds numbers ranging from 8,000 at the root to 28,000 at the tip.While at 200 rotations per minute, the fan blade may experience Reynoldsnumbers ranging from 33,000 at the root to 110,000 at the tip. At speedsbelow 180 rotations per minute, the entire blade may experience Reynoldsnumbers less than 100,000. Accordingly, the airfoils described byParker, et al. may operate below their optimal performance under themajority of operating conditions for the ceiling fan. Furthermore,airfoil blades of the types disclosed in Parker, et al. may increasemanufacturing complexity since the airfoil thickness has a teardropprofile and varies substantially from leading edge to trailing edge. Insome instances, to create this teardrop profile the blade must bemanufactured by plastic injection molding or, alternatively, machinedfrom a flat sheet material, which may result in significant wastage.Thus, a need exists for an improved blade design that offers optimalairflow performance at the low Reynolds numbers experienced by a ceilingfan and is capable of being manufactured by simple techniques usingsustainable materials.

While several systems and methods have been made and used for ceilingfan blades, it is believed that no one prior to the inventors has madeor used the invention described in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

While the specification concludes with claims which particularly pointout and distinctly claim this technology, it is believed this technologywill be better understood from the following description of certainexamples taken in conjunction with the accompanying drawings, in whichlike reference numerals identify the same elements and in which:

FIG. 1 depicts a front perspective view of an exemplary fan having aplurality of exemplary ceiling fan blades attached thereto;

FIG. 2 depicts an exploded perspective view of the fan of FIG. 1;

FIG. 3 depicts an side elevation view of the fan of FIG. 1;

FIG. 4 depicts a plan view of the exemplary ceiling fan blade of FIGS.1-3;

FIG. 4A depicts a cross-sectional view of the ceiling fan blade of FIG.4 taken along section line A-A of FIG. 4;

FIG. 4B depicts a cross-sectional view of the ceiling fan blade of FIG.4 taken along section line B-B of FIG. 4;

FIG. 4C depicts a cross-sectional view of the ceiling fan blade of FIG.4 taken along section line C-C of FIG. 4;

FIG. 5 depicts a combination cross-sectional view of the blade sectionsshown in FIGS. 4A-4C, showing the relative curvature of each section;

FIG. 6 depicts a front elevation view of the fan blade of FIGS. 1-5;

FIG. 7 depicts a perspective view of an alternative fan having aplurality of exemplary ceiling fan blades attached thereto;

FIG. 8 depicts an exploded perspective view of the fan of FIG. 7;

FIG. 9 depicts a plan view of the exemplary fan blade of FIG. 7; and

FIG. 10 depicts an elevation view taken from a root end of the fan bladeof FIG. 9.

The drawings are not intended to be limiting in any way, and it iscontemplated that various embodiments of the technology may be carriedout in a variety of other ways, including those not necessarily depictedin the drawings. The accompanying drawings incorporated in and forming apart of the specification illustrate several aspects of the presenttechnology, and together with the description serve to explain theprinciples of the technology; it being understood, however, that thistechnology is not limited to the precise arrangements shown.

DETAILED DESCRIPTION

The following description of certain examples of the technology shouldnot be used to limit its scope. Other examples, features, aspects,embodiments, and advantages of the technology will become apparent tothose skilled in the art from the following description, which is by wayof illustration, one of the best modes contemplated for carrying out thetechnology. As will be realized, the technology described herein iscapable of other different and obvious aspects, all without departingfrom the technology. Accordingly, the drawings and descriptions shouldbe regarded as illustrative in nature and not restrictive.

I. Exemplary Fan Overview

Referring to FIG. 1, a fan (10) of the present example comprises asupport (20), a motor (30) (shown in FIG. 2), and a plurality of fanblades (50). While three fan blades (50) are shown, it should beunderstood that any other suitable number of fan blades (50) may beused. Fan blades (50) of the present example may define a fan diameterranging from approximately 0.5 meters (1.64 feet), inclusive, toapproximately 5 meters (16.4 feet), inclusive. In the present example,fan blades (50) define a fan diameter of approximately 1.5 meters (4.92feet). Alternatively, fan (10) and/or fan blades (50) may have any othersuitable dimensions.

Support (20) is configured to be coupled to a surface or other structureat a first end such that fan (10) is substantially attached to thesurface or other structure. Support (20) of the present examplecomprises an elongate metal tube-like structure that couples fan (10) toa ceiling, though it should be understood that support (20) may beconstructed and/or configured in a variety of other suitable ways aswill be apparent to one of ordinary skill in the art in view of theteachings herein. In one merely exemplary version, support (20) isconfigured to couple to an electrical junction box (not shown) locatedwithin or on a ceiling. With support (20) comprising an elongate metaltube, wires or other power supply or control members are extendedthrough support (20) to motor (30). By way of example only, support (20)need not be coupled to a ceiling or other overhead structure, andinstead may be coupled to a wall or to the ground. For instance, support(20) may be positioned on the top of a post that extends upwardly fromthe ground. Alternatively, support (20) may be mounted in any othersuitable fashion at any other suitable location. This includes, but isnot limited to, the teachings of the patents, patent publications, orpatent applications cited herein. By way of example only, support (20)may be configured in accordance with the teachings of U.S. Pat. Pub. No.2009/0072108, entitled “Ceiling Fan with Angled Mounting,” publishedMar. 19, 2009, the disclosure of which is incorporated by referenceherein. As yet another alternative, support (20) may have any othersuitable configuration.

As shown in FIG. 2, fan (10) of the present example includes a motor(30) that is coupled to fan blades (50). Motor (30) of the presentexample is coupled to fan blades (50) via fasteners (32). Fasteners (32)may include screws, bolts, clips, clamps, and/or any other suitablefastener (32) for coupling fan blades (50) to motor (30). Alternatively,fasteners (32) may be omitted and fan blades (50) may be adhesivelyattached or integrally formed with a portion of motor (30) such that fanblades (50) rotate when motor (30) is operated. In the present example,a blade shoe (40) is interposed between motor (30) and each fan blade(50). In some versions, blade shoe (40) may comprise a rubber, syntheticrubber, or other vibratory buffering material such that fan blades (50)are substantially isolated from vibrations of motor (30) and/or otherportions of fan (10). Alternatively, blade shoe (40) may comprise aplastic, metal, wood, composite, and/or any other material. Of course itshould be understood that blade shoe (40) is merely optional and may beomitted.

In some versions, motor (30) comprises an AC induction motor having adrive shaft, though it should be understood that motor (30) mayalternatively comprise any other suitable type of motor (e.g., apermanent magnet brushless DC motor, a brushed motor, an inside-outmotor, etc.). In the present example, motor (30) is fixedly coupled tosupport (20) and is configured to rotate fan blades (50) relative tosupport (20) such that air is propelled by fan (10) away from thestructure to which support (20) is coupled. In an alternative version,shown in FIGS. 7-10, a hub (430) may be included in addition to, orinstead of, blade shoes (40). In the version shown in FIGS. 7-10, hub(430) comprises an annular member having a plurality of holes (432)disposed about the circumference to which fan blades (50) may becoupled. Hub (430) is coupled to motor (30) such that rotation of hub(430) by motor (30) rotates fan blades (50). Of course motor (30) may beconstructed in accordance with at least some of the teachings of U.S.Pat. Pub. No. 2009/0208333, entitled “Ceiling Fan System with BrushlessMotor,” published Aug. 20, 2009, the disclosure of which is incorporatedby reference herein. Furthermore, fan (10) may include controlelectronics that are configured in accordance with at least some of theteachings of U.S. Pat. Pub. No. 2010/0278637, entitled “Ceiling Fan withVariable Blade Pitch and Variable Speed Control,” published Nov. 4,2010, the disclosure of which is incorporated by reference herein. Ofcourse, motor (30), blade shoe (40), and/or hub (430) may have any othersuitable components, configurations, functionalities, and operability,as will be apparent to those of ordinary skill in the art in view of theteachings herein.

In the present example, fan (10) further includes a top cover (34). Topcover (34) comprises a dome-shaped component configured to enclose thetop of motor (30). Top cover (34) of the present example is attached tosupport (20) to form a dome over the top of motor (30) when motor (30)is coupled to support (20). In some versions, top cover (34) isthreadably coupled to support (20). In other versions, top cover (34)may be integrally formed with support (20), coupled via fasteners (notshown), or otherwise attached to support (20) and/or motor (30). Whenfan blades (50) of the example shown in FIGS. 1-3 are coupled to motor(30), fan blades (50) and top cover (34) substantially enclose motor(30), as seen best in FIG. 1.

Fan blades (50) of the example shown in FIGS. 1-6 each include anarcuate cutout (54) at a root end (52) of each fan blade (50). When fanblades (50) are coupled to motor (30), arcuate cutouts (54) form acylindrical aperture (56). A semi-transparent lens (48) is inserted intoaperture (56). A sensor (not shown) is mounted within aperture (56) andis configured to receive infrared signals from a remote control (notshown) or other source. The sensor is coupled to a motor control modulethat is operable to control fan (10). Fan (10) may be further configuredin accordance with at least some of the teachings of the fan systemsdisclosed in U.S. Pat. Pub. No. 2009/0097975, entitled “Ceiling Fan withConcentric Stationary Tube and Power-Down Features,” published Apr. 16,2009, the disclosure of which is incorporated by reference herein; U.S.Pat. Pub. No. 2009/0162197, entitled “Automatic Control System andMethod to Minimize Oscillation in Ceiling Fans,” published Jun. 25,2009, the disclosure of which is incorporated by reference herein; U.S.Pat. Pub. No. 2010/0291858, entitled “Automatic Control System forCeiling Fan Based on Temperature Differentials,” published Nov. 18,2010, the disclosure of which is incorporated by reference herein; andU.S. Provisional Patent App. No. 61/165,582, entitled “Fan with ImpactAvoidance System Using Infrared,” filed Apr. 1, 2009, the disclosure ofwhich is incorporated by reference herein Still further configurationsfor lens (48), arcuate cutouts (54), aperture (56), and the sensor willbe apparent to one of ordinary skill in the art in view of the teachingsherein. Of course, it should be understood that lens (48), arcuatecutouts (54) and aperture (56) are merely optional and may be omitted.

While some merely exemplary features of fan (10) have been describedherein, it should be understood that fan (10) may have other features,components, and/or configurations as will be apparent to one of ordinaryskill in the art in view of the teachings herein.

II. Exemplary Fan Blades

A single fan blade (50) is shown plan form in FIG. 4 having a root end(52), a tip (70), a leading edge (80) and a trailing edge (90). SectionsA-A, B-B, and C-C are shown in FIG. 4 and correspond to cross-sectionalFIGS. 4A, 4B, and 4C, respectively. Sections A-A, B-B, and C-C will bediscussed in greater detail below. As noted above, root end (52) of thepresent example comprises an arcuate cutout (54) configured to permitlens (48) be inserted in a central aperture (56) formed when fan blades(50) are mounted. Root end (52) further includes a pair of openings (58)that permit fasteners (32) to extend therethrough to couple fan blade(50) to motor (30) and/or hub (42). As shown in FIGS. 1-3, root end (52)of the present exemplary fan blade (50) comprises a domed sector thatcorresponds to an approximately 120 degree sector of a dome for thepresent fan (10) having three fan blades (50). The domed sector of rootend (52) is substantially flat, or parallel, relative to the plane ofrotation for fan blades (50) at or near arcuate cutout (54). The domedsector curves upwardly toward motor (30) and/or support (20). Root end(52) may of course include an approximately 180 degree, 90 degree, 60degree, 45 degree and/or any other sector portion of a dome or may omita domed sector end. Of course other root ends (52) will be apparent toone of ordinary skill in the art in view of the teachings herein.

Fan blade (50) also includes a transition region (60) extending fromroot end (52), shown best in FIGS. 4 and 6. In the present example,transition region (60) comprises a first portion (62), an inflectionportion (64), and a second portion (66). First portion (62) comprises anextension of the domed sector of root end (52) that terminates atinflection portion (64). Inflection portion (64) of the present examplecomprises a quasi-parabolic shaped portion that extends from leadingedge (80) to trailing edge (90) and transitions fan blade (50) from theupwardly extending domed shape of first portion to a planar portion.Second portion (66) extends from inflection portion (64) and transitionsfan blade (50) from the planar inflection portion (64) to the downwardlycurved root airfoil profile (100), shown in FIG. 4A. By way of exampleonly, a non-dimensional matrix of coordinates in Table 1 below generallydescribes the surface formed by transition region (60) and airfoilprofile (100). It should be understood that the domed sector of root end(52) is omitted from the coordinates in Table 1. In addition, the Zcoordinate corresponds to the vertical height of the point at thetransition point from root end (52) (e.g., a height of 0 corresponds towhere root end (52) ends and transition region (60) beings), the Xcoordinate corresponds to the longitudinal distance from a central pointabout which blade (50) rotates, and the Y coordinate corresponds to thechord-wise position, where negative coordinates approach trailing edge(90) and positive coordinates approach leading edge (80).

TABLE 1 Z X Y 0 0.0892 −0.01 0 0.0991 −0.009 0 0.1072 −0.008 0 0.1145−0.007 0 0.1209 −0.006 0 0.1263 −0.005 0 0.1305 −0.004 0 0.1337 −0.003 00.1358 −0.002 0 0.137 −0.001 0 0.1373 0 0 0.1366 0.001 0 0.1351 0.002 00.1327 0.003 0 0.1294 0.004 0 0.1252 0.005 0 0.1201 0.006 0 0.1141 0.0070 0.1071 0.008 0 0.0989 0.009 0 0.0888 0.01 0.005 0.0986 −0.01 0.0050.1273 −0.009 0.005 0.1897 −0.008 0.005 0.1452 −0.007 0.005 0.1471−0.006 0.005 0.1521 −0.005 0.005 0.1564 −0.004 0.005 0.1595 −0.003 0.0050.1614 −0.002 0.005 0.1621 −0.001 0.005 0.1617 0 0.005 0.1602 0.0010.005 0.1578 0.002 0.005 0.1544 0.003 0.005 0.1501 0.004 0.005 0.1450.005 0.005 0.139 0.006 0.005 0.1322 0.007 0.005 0.1248 0.008 0.0050.1166 0.009 0.01 0.4002 −0.007 0.01 0.3408 −0.006 0.01 0.286 −0.0050.01 0.1931 −0.004 0.01 0.1902 −0.003 0.01 0.1913 −0.002 0.01 0.1909−0.001 0.01 0.1892 0 0.01 0.1863 0.001 0.01 0.1824 0.002 0.01 0.17760.003 0.01 0.1718 0.004 0.01 0.1653 0.005 0.01 0.1581 0.006 0.01 0.15030.007 0.01 0.1421 0.008 0.015 0.4724 −0.007 0.015 0.4133 −0.006 0.0150.3586 −0.005 0.015 0.3085 −0.004 0.015 0.2616 −0.003 0.015 0.2246−0.002 0.015 0.2212 −0.001 0.015 0.2175 0 0.015 0.2126 0.001 0.0150.2067 0.002 0.015 0.2 0.003 0.015 0.1926 0.004 0.015 0.1846 0.005 0.0150.1762 0.006 0.015 0.1675 0.007 0.015 0.1585 0.008 0.02 0.5299 −0.0070.02 0.4852 −0.006 0.02 0.4308 −0.005 0.02 0.3807 −0.004 0.02 0.3352−0.003 0.02 0.2942 −0.002 0.02 0.2551 −0.001 0.02 0.2442 0 0.02 0.23690.001 0.02 0.2289 0.002 0.02 0.2204 0.003 0.02 0.2115 0.004 0.02 0.20230.005 0.02 0.1929 0.006 0.02 0.1834 0.007 0.02 0.1745 0.008 0.025 0.5627−0.006 0.025 0.5024 −0.005 0.025 0.4526 −0.004 0.025 0.4072 −0.003 0.0250.3662 −0.002 0.025 0.3296 −0.001 0.025 0.2975 0 0.025 0.2696 0.0010.025 0.2502 0.002 0.025 0.2395 0.003 0.025 0.2297 0.004 0.025 0.22030.005 0.025 0.2117 0.006 0.025 0.2042 0.007 0.025 0.1988 0.008 0.030.5734 −0.005 0.03 0.5241 −0.004 0.03 0.4789 −0.003 0.03 0.438 −0.0020.03 0.4014 −0.001 0.03 0.3692 0 0.03 0.3412 0.001 0.03 0.3175 0.0020.03 0.2977 0.003 0.03 0.2818 0.004 0.03 0.2696 0.005 0.03 0.2614 0.0060.03 0.2566 0.007 0.03 0.2548 0.008 0.035 0.595 −0.004 0.035 0.5502−0.003 0.035 0.5095 −0.002 0.035 0.473 −0.001 0.035 0.4408 0 0.0350.4128 0.001 0.035 0.3891 0.002 0.035 0.3693 0.003 0.035 0.3535 0.0040.035 0.3414 0.005 0.035 0.333 0.006 0.035 0.328 0.007 0.035 0.32640.008 0.04 0.6211 −0.003 0.04 0.5808 −0.002 0.04 0.5445 −0.001 0.040.5124 0 0.04 0.4844 0.001 0.04 0.4606 0.002 0.04 0.4409 0.003 0.040.4252 0.004 0.04 0.4133 0.005 0.04 0.4051 0.006 0.04 0.4005 0.007 0.040.3994 0.008

Of course, it should be understood that other configurations fortransition region (60) and/or other regions of fan blade (50) may beused. For instance, if root end (52) omits a domed sector, then fanblade (50) may omit first portion (62) and, in some versions, inflectionportion (64), having only second portion (66) transition to root airfoilprofile (100) directly. Still further constructions for transitionregion (60), etc., will be apparent to one of ordinary skill in the artin view of the teachings herein.

Referring now to FIG. 4A, a cross-sectional root airfoil profile (100)is shown taken along section A-A of FIG. 4. Root airfoil profile (100)comprises a top surface (102), a bottom surface (104), a leading edge(106), and a trailing edge (108). Root airfoil profile (100) of thepresent example comprises a curved airfoil having a substantiallyconstant thickness (110) and a substantially constant radius ofcurvature (120). By way of example only, thickness (110) may range fromapproximately 1 millimeter (0.03937 inches), inclusive, to approximately5 millimeters (0.19685 inches), inclusive. In the example shown,thickness (110) is approximately 4 millimeters (0.15748 inches) thoughthis is merely one embodiment. Still further values for thickness (110)will be apparent to one of ordinary skill in the art in view of theteachings herein. Also by way of example only, radius of curvature (120)is measured from a center point (118) and may range from approximately 2meters (6.56167 feet), inclusive, to approximately 5 meters (16.4042feet), inclusive. In the example shown, radius of curvature (120) isapproximately 3.7 meters (12.1391 feet). Still further values for radiusof curvature (120) will be apparent to one of ordinary skill in the artin view of the teachings herein. In the example shown in FIG. 4A, rootairfoil profile (100) is defined when radius of curvature (120) is sweptthrough a root angle (122). Root angle (122) of the present example isapproximately 14 degrees, though it should be understood that this ismerely exemplary and other smaller and/or larger root angles (122) willbe apparent to one of ordinary skill in the art in view of the teachingsherein. Furthermore, leading edge (106) and trailing edge (108) compriserounded surfaces connecting top surface (102) to bottom surface (104),though this is merely optional. Leading edge (102) and trailing edge(104) of the present example form rounded surfaces having a radius ofcurvature substantially equal to thickness (110). Thus, as shown in FIG.4A, a substantially constant thickness root airfoil profile (100) isformed.

FIG. 4B depicts a cross-sectional intermediate airfoil profile (200)taken along section B-B of FIG. 4 at an approximate midpoint betweenroot airfoil profile (100) and tip airfoil profile (300), discussed ingreater detail below. It should be understood that while the termintermediate is used, it does not necessarily connote that the shape,size, or values defining intermediate airfoil profile (200) are inbetween those of root airfoil profile (100) and tip airfoil profile(300). Intermediate airfoil profile (200) of the present examplecomprises a top surface (202), a bottom surface (204), a leading edge(206), and a trailing edge (208). Intermediate airfoil profile (200) ofthe present example is substantially identical to root airfoil profile(100) and has a substantially identical thickness (110) and is definedby a substantially identical radius of curvature (120) with theexception that radius of curvature (120) is swept through anintermediate angle (222). By way of example only, intermediate angle(222) is approximately 12.5 degrees, though of course other smallerand/or larger intermediate angles (222) will be apparent to one ofordinary skill in the art in view of the teachings herein.

FIG. 4C shows a cross-sectional tip airfoil profile (300) taken alongsection C-C of FIG. 4 at an approximate tip (70) of fan blade (50). Tipairfoil profile (300) of the present example comprises a top surface(302), a bottom surface (304), a leading edge (306), and a trailing edge(308). Tip airfoil profile (300) of the present example is substantiallyidentical to root airfoil profile (100) and has a substantiallyidentical thickness (110) and is defined by a substantially identicalradius of curvature (120) with the exception that radius of curvature(120) is swept through a tip angle (322). By way of example only, tipangle (322) is approximately 7 degrees, though of course other smallerand/or larger tip angles (322) will be apparent to one of ordinary skillin the art in view of the teachings herein.

FIG. 5 depicts a composite overlay of the cross-sections of FIGS. 4A-4C.As noted above, root airfoil profile (100), intermediate airfoil profile(200), and tip airfoil profile (300) are substantially identical inshape and thickness with the exception of each being formed by sweepingradius of curvature (120) to various angle (122, 222, 322). In someversions, the tip angle (322) is a minimum value for the angles throughwhich radius of curvature (120) is swept while root angle (122) is amaximum value for fan blade (50). Though, it should be understood thattip angle (322) need not necessarily be the minimum value for the anglesthrough which radius of curvature (120) is swept and/or root angle (122)need not necessarily be the maximum value for the angles through whichradius of curvature (120) is swept. In addition, or in the alternative,angles (122, 222, 322) may linearly increase in value from tip angle(322) to root angle (122). In other versions, angles (122, 222, 322) mayincrease in value logarithmically, parabolically, cubically, and/or inany other manner from tip angle (322) to root angle (122). Referringbriefly to FIG. 6, fan blade (50) is also configured to have a bladerise angle (98). In the example shown, blade rise angle (98) correspondsto the angle formed between the plane in which the fan rotates and thetop surface of fan blade (50). Thus, the absolute height of each fanblade (50) increases from root end (52) to tip (70). By way of exampleonly, blade rise angle (98) may be an angle of approximately 0 degrees,inclusive, to approximately 20 degrees, inclusive. More specifically,blade rise angle (98) may be from 2.5 degrees, inclusive, to 5 degrees,inclusive. In the example shown, blade rise angle (98) is approximately3.8 degrees. Still further configurations for airfoil profiles (100,200, 300) and/or fan blade (50) will be apparent to one of ordinaryskill in the art in view of the teachings herein. By way of exampleonly, flaps, slats, extensions, electrical or mechanical actuators,and/or other features may be added to fan blades (50).

Fan blade (50) of the present example is manufactured from thin sheetsof material laminated together. For instance, fan blade (50) may beconstructed by combining individual sheets with adhesive between eachlayer and forcing the sheets together under pressure in a shaped mold toform fan blade (50) shown in FIGS. 1-6. By way of example only, fanblade (50) may be manufactured using 7 layers of 0.5 millimeter(0.019685 inches) thick bamboo veneer that are compressed together asdescribed above. Of course other thicknesses and/or number of layers maybe used. Alternatively, other types of wooden veneer may be used or maybe combined with other woods to form composite fan blades (50). In yet afurther alternative, fan blade (50) may be formed from of athermoplastic resin that is injected into a mold for fan blade (50) toachieve the desired profile. Further still, fan blade (50) may be formedfrom a single layer of plastic that is heated and bent or inserted intoa mold to form the profile of fan blade (50). In still a furtheralternative, fan blade (50) may be formed from layers of fiberglassmatting or carbon fiber composite materials combined with epoxy resins.In yet another alternative, layers of wood veneer or other materials(e.g., carbon fiber, fiberglass, etc.) may initially be layered within amold and plastic or another resin may be injected or otherwise added toform fan blade (50). Of course still further constructions for fan blade(50) will be apparent to one of ordinary skill in the art in view of theteachings herein.

III. Exemplary Alternative Fan

FIGS. 7-10 depict an alternative fan (400) having a support (410), amotor (420), a hub (430), and a plurality of fan blades (450). Support(410) and motor (420) of the present example may be constructed insubstantial accordance with support (20) and motor (30) described above.Hub (430), shown best in FIG. 8, comprises an annular member disposedabout and coupled to motor (420) such that rotation of motor (420)rotates hub (430). Hub (430) further includes a plurality of holes (432)to which fasteners (434) may be coupled to substantially fixedly coupledfan blades (450) with hub (430). Accordingly, when motor (420) rotates,fan blades (450) and hub (430) also rotate. It should be understood thatadditional components, such as grommets or other vibratory-reducingmembers may be included between fan blades (450) and hub (430) and/orbetween hub (430) and motor (420). In the present example, fan (400)further includes a top cover (412) having a circular center (not shown)and a plurality of rectangular fan extensions (414). In the presentexample, rectangular fan extensions (414) curve downwardly relative tosupport (410) and are configured to nest within top recesses (454)formed in fan blades (450), described below, to form a substantiallysmooth transition between top cover (414) and fan blades (450).

A circular bottom cover (416) includes a plurality of upwardlyprojecting L-shaped tabs (418) disposed about the circumference ofbottom cover (416) and a central lens (419). Lens (419) may beconstructed in accordance with lens (48) described above. Bottom cover(416) is configured to couple to a bottom portion of fan blades (450)via tabs (418) inserting into recesses (not shown) formed in fan blades(450) and then being rotated such that an axial projection from each tablocks into the recesses. Accordingly, when bottom cover (416) is coupledto fan blades (450), a substantially smooth lower surface for fan (400)is formed. Of course it should be understood that bottom cover (416) maycouple to fan blades (450) through other attachment members, such asscrews, bolts, clips, clamps, straps, resilient tabs, etc. In addition,or in the alternative, bottom cover (416) may be directly coupled tomotor (420). Fan (400) may be further configured in accordance with theteachings of fan (10) described above or in any other manner as will beapparent to one of ordinary skill in the art in view of the teachingsherein.

Referring now to FIGS. 9-10, fan blade (450) of the present examplecomprises a root end (452), a tip (470), a leading edge (480), and atrailing edge (490). Fan blade (450) of the present example comprisesairfoil profiles that substantially correspond to airfoil profiles (100,200, 300) described above. In the present example, however, fan blade(450) comprises an alternative root end (452) and transition region(466). Transition region (466) of the present example comprises atapered portion of fan blade (450) that transitions from root end (452)to airfoil profiles (100, 200, 300) for fan blade (450). Root end (452)of the present example includes a top recess (454) configured to receivea respective extension (414) therein. Thus, when extensions (414) arenested within respective top recesses (454) a substantially smoothtransition is formed from top cover (414) to fan blades (450) for fan(400). In addition, one or more openings (456) are formed through alower portion of root end (452) to permit fasteners (434) therethroughto substantially fixedly coupled fan blade (450) to hub (430) describedabove.

Root end (452) is further includes a recessed ledge (458) and an outerlip (460) disposed on opposing ends of root end (452). As shown in FIGS.8-9, recessed ledge (458) corresponds to the side of fan blade (450)with leading edge (480) while outer lip (460) corresponds to the side offan blade (450) with trailing edge (490). Accordingly, when fan blades(450) are assembled for fan (400), recessed ledge (458) nests with andbelow outer lip (460) of the fan blade (450) to form a substantiallysmooth and continuous surface from one fan blade (450) to the next. Inthe present example, fan blades (450) have root ends (452) with recessedledges (458) and outer lips (460) disposed approximately 120 degreesfrom each other such that three fan blades (450) may be combined to forma substantially continuous fan blade structure (as shown in FIG. 7). Ofcourse it should be understood that other angular relationships may beused as well (e.g., 180 degrees for a dual fan blade (450) assembly, 90degrees for a four fan blade (450) assembly, 60 degrees for a five fanblade (450) assembly, etc.). In addition, or in the alternative,fasteners (not shown) may be used to couple corresponding recessedledges (458) and outer lips (460) together for fan blades (450). Furtherstill, rubber grommets (not shown) or other vibratory-reducing membersmay be interposed between corresponding recessed ledges (458) and outerlips (460) to vibrationally isolate fan blades (450) from one another.In the present example, a pair of rib members (462) are provided withinroot end (452) to reinforce or otherwise provide additional rigidity toroot end (452), though these are merely optional. Still furtherconstructions for root end (452) and/or fan blade (450) will be apparentto one of ordinary skill in the art in view of the teachings herein.

Fan blade (450) of the present example is manufactured by athermoplastic resin that is injected into a mold for fan blade (450) toachieve the desired profile. Alternatively, fan blade (450) may beformed from thin sheets of material laminated together and anchored to athermoplastic or other material root end (452). For instance, fan blade(450) may be constructed by combining individual sheets with adhesivebetween each layer and forcing the sheets together under pressure in ashaped mold to form fan blade (450) shown in FIGS. 9-10 and anchored toroot end (452). In one version, fan blade (450) may be manufacturedusing 7 layers of 0.5 millimeter (0.019685 inches) thick bamboo veneerthat are compressed together as described above. Of course otherthicknesses and/or number of layers may be used. Alternatively, othertypes of wooden veneer may be used or may be combined with other woodsto form composite fan blades (450). Further still, fan blade (450) maybe formed from a single layer of plastic that is heated and bent orinserted into a mold to form the profile of fan blade (450) which issubsequently joined to root end (452). In still a further alternative,fan blade (450) may be formed from layers of fiberglass matting orcarbon fiber composite materials combined with epoxy resins. In yetanother alternative, layers of wood veneer or other materials (e.g.,carbon fiber, fiberglass, etc.) may initially be layered within a moldand plastic or another resin may be injected or otherwise added to formfan blade (450). Of course still further constructions for fan blade(450) will be apparent to one of ordinary skill in the art in view ofthe teachings herein.

It should be appreciated that any patent, publication, or otherdisclosure material, in whole or in part, that is said to beincorporated by reference herein is incorporated herein only to theextent that the incorporated material does not conflict with existingdefinitions, statements, or other disclosure material set forth in thisdisclosure. As such, and to the extent necessary, the disclosure asexplicitly set forth herein supersedes any conflicting materialincorporated herein by reference. Any material, or portion thereof, thatis said to be incorporated by reference herein, but which conflicts withexisting definitions, statements, or other disclosure material set forthherein will only be incorporated to the extent that no conflict arisesbetween that incorporated material and the existing disclosure material.

Having shown and described various embodiments of the present invention,further adaptations of the methods and systems described herein may beaccomplished by appropriate modifications by one of ordinary skill inthe art without departing from the scope of the present invention.Several of such potential modifications have been mentioned, and otherswill be apparent to those skilled in the art. For instance, theexamples, embodiments, geometrics, materials, dimensions, ratios, steps,and the like discussed above are illustrative and are not necessarilyrequired. Accordingly, the scope of the present invention should beconsidered in terms of the following claims and is understood not to belimited to the details of structure and operation shown and described inthe specification and drawings.

What is claimed is:
 1. A fan blade configured to mount to a rotating fanhub, the fan blade comprising: a. a root end configured to couple withthe rotating fan hub, wherein a profile of the root end comprises asubstantially convex top surface and a substantially concave domedsector; b. a blade region, wherein a profile of the blade regioncomprises a substantially convex top surface and bottom surface; c. atransition region extending between the root end and the blade region,wherein the transition region comprises a profile which transitions theroot end profile to the blade region profile; d. a leading edge; e. atrailing edge; and f. a tip, wherein the leading edge and trailing edgeterminate into the tip.
 2. The fan blade of claim 1, wherein the rootend comprises an arcuate cutout.
 3. The fan blade of claim 2, whereinthe domed sector is configured to terminate into a region which isparallel to a plane of rotation of the fan blade at a position proximalto the arcuate cutout.
 4. The fan blade of claim 3, wherein thetransition portion comprises a first potion, an inflection portion, anda second potion.
 5. The fan blade of claim 4, wherein the first portioncomprises an extension of the concave domed sector of the root end whichterminates at the inflection portion.
 6. The fan blade of claim 5,wherein the inflection portion comprises a quasi-parabolic shapedportion that extends from the leading edge to the trailing edge andtransitions the fan blade from the extension of the concave domed sectorof the first portion to a planar portion.
 7. The fan blade of claim 6,wherein the second portion extends from the inflection portion and theplanar portion to the profile of the blade region.
 8. The fan blade ofclaim 7, wherein the top surface of the profile of the blade regioncomprises: a first top convex curvature proximal to the second portionof the transition region, and a second top convex curvature proximal tothe tip.
 9. The fan blade of claim 8, wherein the bottom surface of theprofile of the blade region comprises a first bottom convex curvatureproximal to the second portion of the transition region, and a secondbottom convex curvature proximal to the tip.
 10. The fan blade of claim9, wherein the top surface of the blade region transitions from thefirst top convex curvature to the second top convex curvature along alength of the blade region.
 11. The fan blade of claim 10, wherein thebottom surface of the blade region transitions from the first bottomconvex curvature to the second bottom convex curvature along the lengthof the blade region.
 12. The fan blade of claim 11, wherein the bottomsurface of the blade region slopes upward along the length of the bladeregion.
 13. The fan blade of claim 12, wherein the top surface of theblade region slopes upward along the length of the blade region.
 14. Thefan blade of claim 13, wherein the leading edge is located at a positionhigher than a position of the trailing edge.
 15. The fan blade of claim14, wherein the tip is curved.
 16. A fan assembly comprising: a. a fanmotor; b. a fan hub, wherein the fan hub is attached to the fan motor;and c. the fan blade of claim 14, wherein the fan blade is one of aplurality of similar fan blades mounted to the fan hub.
 17. A fan bladeconfigured to mount to a rotating fan hub, the fan blade comprising: a.a root end, wherein the root end comprises: i. a root end profilecomprising a concave bottom surface and a convex top surface, ii. acutout on the bottom surface configured to receive a bottom surface ofthe fan hub, iii. a plurality of holes configured to allow the root endto be coupled to the rotating fan hub, and iv. a cutout on the topsurface configured to receive a top surface of the fan hub; b. a bladeregion, wherein a profile of the blade region comprises a substantiallyconvex top surface and bottom surface; and c. a transition regionlocated between the root end and the blade region, wherein a profile ofthe transition region transitions the profile of the root end into theprofile of the blade region.
 18. The fan blade of claim 17, wherein therelief on the top surface of the root end is substantially square inshape.
 19. The fan blade of claim 18, wherein the bottom surface of theroot end is configured to terminate into a region which is parallel to aplane of rotation of the fan blade at a position proximal to the cutout.20. A fan assembly, wherein the fan assembly comprises: a. a fan motor;b. a fan hub, wherein the fan hub is coupled to the fan motor; and c. aplurality of fan blades, wherein each one of the fan blades of theplurality of fan blades comprises: i. a root end capable of beingcoupled to the rotating fan hub, wherein a profile of the root endcomprises a substantially convex top surface and a substantially concavedomed sector, ii. a blade region, wherein a profile of the blade regioncomprises a substantially convex top surface and bottom surface, andiii. a transition region extending between the root end and the bladeregion, wherein the transition region comprises a profile whichtransitions the root end profile to the blade region profile.